Attachment plug



Feb. 24, 1942. T, CONRAD ATTACHMENT PLUG Filed April 29, 1940 o O I I v I IQvENToR.

\ Y'oM C'oA/RAD,

ATTORNEY the process of manufacture.

Patented Fgl). 24, 1942 "UNITED STATES PATENT,

OFFICE t ATTACHMENT PLUG TomJ. Conrad, El Segundo, Calif Application April 29,1940, se ial No. 332,201 7 -2 Claims. (Cl.173 -361) This invention relates to electrical attachment plugs ofthe ,typefused to connect'electrical appliances to wall outlets, screw plugs, and the like. 7

.It is an object of this invention to provide a simple type of connector which can be readily connected to an outlet of standard design.

It is a further object of this invention to pro vide a plug which can be secured to an outlet against accidental removal.

It is a further object of this invention to provide a'connector plug which can be readily inserted and removed.

It is a further object of this invention to provide a plug which can be readily assembled in 7 of the resiliency of the plug body.

This invention possesses many other advantages and has" other objects which may be made in place. Barbs l3 are also provided for a purpose hereinafter described. A plurality of conductor wiresf l4 of usual form may be soldered or otherwise suitably attached to strips H5.

The strips I l are made of spring material such as phosphor-bronze or other spring material possessing good electrical conducting qualities.

As clearly shown inFigure 3, these strips are formed with an'extended concave portion l5 to increase the stifiness of the major portion-thereof. An ofiset portion I6 is formed in the length of the strips, and said strips curve inwardly therefrom so that the ends of the strips are inwardly of the plane of the major portion of the strips, as shown in Figure 3. The curved portions I! are provided with struck-up portions l8.

In order to prevent contact between the two spring strips II a block 20 of a resilient mate- .rial is provided therebetween. This block may have openings .2I therein to receive the barbs I3. It may also be provided without out portions 22 to clear the conductors l4, Upon assembly, the strips H are simply fastened to the conductors and pulled into place in the plug. Block 20 more easily apparent from a consideration'of one embodiment of the invention. For this purpose there is shown a form in the drawing accompanying and forming partof the present specification. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is'not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings: v

Figure 1 is a perspective view of one form of this invention.

may then' be inserted between the strips ll. When the assembly is complete, the barbs I! hold the strips in place, and barbs l3 in turn hold the block 20 in position.

When assembled, the curved ends 11 of the strips are separated by an amount suflicient to clear the center separator 25 of an outlet 26, to

. allow easy insertion in the outlet. As the plug is forced home. the curved portions engage the outside walls of the slots in the socket, and the strips move toward each other, allowing the offset portions to clear the wall and snap out to the 1 position shown in Figure 2. The upstruck por- Figure 2 is a view partly in section of a plug made in accordance with this invention inserted in an outlet.

Figure 3 is an expanded view partly in section of the deviceof Figure 1;and,j

Figure, 4 is an assembled ,view of the parts shown in Figure 3.

This plug consists of a resilient body It] having metal contacting members inserted therein. These contacting members consist of elongated strips of metal ll provided withbarbs I2 for entions [8 on the curved portions I! of the strips provide a'means for forcing the outlet contacts 21 away from the center separator 25, and; as the strip ends are curved to roughly correspond "to the contacts 21, a good contact between the strips and contacts 21 is assured.

It will be noted that the agency causing 'engagement between .the oiTset portions and the underside. of the wall of the outlet is chiefly the resiliency of the ends'll of the strips 'II, and not. the-resiliency of a the body I0 of the plug. Thisinsures that aging of the material and consequent loss of. resiliency will not render the holding means ineffective. Provision of the concave portions I5 on strips Il insures that squeezing ofthe resilient body In by-the sides will cause the oifsetiportions IE to approach each other gagement with the body Hi to secure the strips suiiiciently to clear the engaging shoulders of the receptacle 26 to permit removal of the plug.

If the stiffness created by the concavity o! the strips H were not provided, application of pressure to the sides of the plug would merely cause bending of the strips over their entire-length 1. An attachment plug comprising a yieldable' body, a plurality of contact members in said body and projecting therefrom, said contact members each having the portion within'said tion extending to the other side of the plane of the contact member from the offset portion, whereby the offset portion is forced into engagement with the body of the receptacle by the resiliency of the contact member and squeezing of the yieldable body causes bending of the resilient portions of the contact members to disengage the ofiset portions from the receptacle.

2. An attachment plug comprising a. yieldable body, a plurality of contact members in said body and projecting therefrom, means preventing a portion of each of the contact members within said body from bending, the portion without said body being of resilient construction, an offset portron on the resilient portion of each contact memher, the offset portion of each of the contact members cooperating to engage under the body of a receptacle, and a portion extending beyond the oilset portion'for engaging a contact of the body formed to prevent bending, and'the portion I I withoutsaid bodyof resilient'construction, an

offset portion on the resilient portion of each contact member, the oifset portion of each of the contact members cooperating to ensageunder the body of a receptacle, and 8. portion extending beyond the ofiset portion for engaging a contact of the receptacle, said last mentioned porreceptacle, said last mentioned portion extending to the other side of the plane of the contact member from the offset portion, whereby the offset portion is forced into engagement with the body of the receptacle by the resiliency of the contact member, and squeezing of the yieldable body causes bending of the resilient portions of the contact members to disengage the offset portions from the receptacle.

TOM J. CONRAD. 

